Dragline excavator



1940. o. J. MAR-rlNsoN 2,214,025 DRAGLINE EXcAvAToP.

Filed Oct. 17, 1958 '7 Sheets-Sheet l 'lll /m/w/o/ 0560/ Maf/7050 o. J. MARTINSON l DRAGLINE EXcAvAToF.

Filed Oct. 17, 1938 Sept. l0, 1940.

7 Sheets-Sheet 2 Sept. l0, 1940. Yvo. J. MARTlNsoN DRAGLINE EXcAvAToP.

Filed oct. 17, 1938 7 Sheets-Sheet 5 //7 l/@n .for O5@ 0f J Ma/750m Sept. l0, 1940. o. J. MARTlNsoN .2,214,026

DRGLINE EXCAVATP.

Filed Oct. 17, 1938 7 Sheecs-Sheec4vr //7 VQ fof 0560/: J. Mar/#750m Sept. 10,' 1940.

- o. J. MARTlNsoN 2,214,026'

l DRAGLINE ExcAvAToP.

Filed Oct. 17, 1938 7 Sheets-Sheet 5 /fv van for 0560/ J Maf/#750 m2 f /fdmam/A f/ys.

SPf l0, 1940. o. J. MAR'nNsoN 2,214,026

DRAGLINE EXCAVATOP.

Filed Oct. 17, 1938 "7 Sheets-Sheet 7 Patented Sept. 10, 1940 PTENT OFFICE DRAGLINE. EXCAVATOR scar J. Martinson, Chicago, Ill., assigner to Bucyrus-Monighan Company, Chicago, Ill., a

corporation of illinois Application `October 17, 1938, Serial No. 235,420

la Claims.

This invention relates to dragline excavator equipment, and the purpose of the invention is to extend the reach or operating range of any dragline excavator of customary construction without necessitating a change of the point of application of lift on `the boom of a loaded bucket. The purpose of the invention is attained by a modicationin rigging wherein the main boom has an extension boom attached thereto without interfering with the normalcy of the rest of the rigging; that is, a hoist line as usual passes: from the bucket over a sheave at the end of the main boom, and the dragline extends from the bucket to operating means in the base-supported m-achinery. There is, however, in the new construction a second hoist line which leads from the bucket around a sheave at the outer end of the extension boom. The function of this second hoist line is to carry an unloaded bucket outwardly away from the machine further than is possible with the normal boom length and without necessity for this hoist line sharing in the lift or support of a loaded, suspended bucket.

A secondary object of the invention is the provision of an improved double hoisting drum unit particularly adapted for this extended boom arrangement.

The drawings illustrate the invention diagrammatically as to the general layout vand in detail in reference to the mounting of the extension boom and to winding drums particularly designed for controlling the .action of companion hoist lines:

Figure l is a diagram showing the improved dragline excavator in side elevation.

Fig. 2 shows in longitudinal section a pair of winding drums for hoist lines.

Fig. 3 is a sectional view on the line 3-3 of Fig. 2.

Fig. l is a fragmentary side View of the main and extension booms showing their pivot connection.

Fig. 5 is another side elevation like Fig. l of the improved dragline excavator, but differs from Fig. l in showing that one of the cables by which the bucket is suspended leads to a counterweighted drum to give this line an automatic action in taking up slack.

Fig. 6 is a pl-an View of the cable winding unit used in the construction shown by Fig. 5.

Fig. 'l shows the Winding unit of Fig. 6 in side elevation.

Fig. S is a plan View of the treadle mechanism for pneumatic control of the brakes for the winding drums shown in Figs. 6 and 7.

Fig. 9 is a side View of the treadle mechanism.

Figs. 10 and 11 are details of the treadles and Fig. 12 is a diagram of a simplified control means for the extra suspension line which leads from the bucket to the extension boom.

The type of dr'agline excavator to which the improvements are here shown as appliedfis of the Main base I Machinery supporting platform 2 Mast 3 Boom 4 Suspension cables 5 Drag bucket 6 Dragline 1 Bucket hoist line 8 Sheaves are located Where necessary and the lines are doubled back and forth between the sheaves when required to reduce the strain on the cables. Y

Improvement of that standard construction is indicated on the drawings as follows:

The particular double hoist line winding drum unit of Figs. 2 and 3,v or the one of Figs. 6 and 7.

Extension boom IB.

A journal or pivot bearing connection Il between the outer end of the main boom and the extension boom.

Suspension cables i2 between the extension boom and the mast.

A sheave I3 at the outer end of the extension boom.

A hoist line i4 leading from the bucket to the extension boom sheave and from there to a winding drum on the machinery platform.

And control means for cable winding drums including an independent or dependent automatic control for the additional hoist or bucket suspension cable added to the rigging because of the extension boom requirements.

The two hoist lines 8 and I4 are operated by means of a power-driven drum unit as indicated in `detail by Fig. 2, or by Figs. 6 and '1. In Fig. 2,

' hoist line llt is anchored to drum iii.

the hoist line t is anchored to drum l5 and the A common drive for the two drums is driven gear il, land this gear is clutched as required to the drum l5 through clutc. iii.

The drinn supporting shaft lil is journalled in bearings at 2i) and El, and the drum it is freely rotatable on the shaft. This drum is frictionally driven from the direct driven drum i through friction clutch shoes Springs 23 provide the necessary contact pressure between the shoes and the drum flange. Differential rotation of the two drums is controlled by use of brakes, brake for drum i5 being represented at and brake for drum i6 being represented at 25.

The pivot mounting of the extension boom lli on the outer end of the main boom Il is detailed in Fig. 4. This figure also indicates the customary hoist line sheave it journalled near the end of main boom 5, and the bucket is as usual suspended from sheave 2S and hoisted when loaded by means of the hoist line 3 passing over the sheave to drum l5.

The dragline l is also operated as usual by a winding drum 2l, Fig. l., and leads from this drum between fair-leaders 28 and 29 at the front end of platform 2 around a block 3b to the attachment point 3l above the mouth of the bucket. The dragline i is connected by chain 32 to the forward end of the bucket below the attachment point 3l. The shell or housing of block 33 is connected by chains with trunnions il@ toward the rear of the bucket. rihe bucket ends of hoist lines 8 and Hl are also attached to the housing of block 3G. With that arrangement, Whenever there is sufncient tension on the dragline l, the bucket is held in its horizontal position and prevented from assuming the unloading vertical position, and this is a common rig for drag buckets with the exception that it is not customary to use two hoist lines.

In the improved construction the customary hoist line S is supplemented by hoist line i4, and the purpose of hoist line ifi which leads over the outer end of the extension boom ill is to enable an unloaded bucket to swing outwardly around a center provided by sheave i3 rather than around Vthe center provided by sheave 25. The normal reach of the machine is thus increased; for example, if the main boom is ft. or so in length, the extension boom lil may be proportioned thereto, as indicated in Fig. l, to increase the reach nearly one-third. Therefore, the function of this extension boom is for increasing the operating range of the excavator by carrying an empty bucket further out, and may be left free of sharing the load of a filled bucket in lifting the loaded bucket and carrying it to the dumping position, as the machine swings on a central axis provided by main base l.

The operation of the machine, without reference to the extension boom and the added hoist line, is as usual carried on by first paying out on hoist line i3 to lower the bucket to the point where it begins the inward filling stroke toward the Then the cycle is repeated by swinging the Ina- `chine back toward working position and paying out on both lines 8 and 'l' to place the bucket for a new lling stroke.

With the improved construction the customary operation may be altered by, after unloading the bucket, effecting a differential paying out of hoist lines and lll, whereby the bucket may be swung outwardly from both the pivots provided by sheaves 2t and itl, or exclusivelyV around the pivot provided by sheave it. The bucket is thus placed outwardly further than it could be with normal boom length. The total support required from the extension boom is that of the weight of the unloaded bucket. The extension boom may therefore be of relatively light construction. After the completion of the lengthened digging stroke the n? ain boorn takes all the load of lifting the loaded bucket through hoist line 8.

The differential winding up and paying out of the hoist lines 8 and lll is effected by use of brakes 'it and Fig. 2. When'drum i5 is used to lift the loaded bucket it must take the load of lifting because of the positive drive with which it is provided, whereas drum i5 may merely take up the slack in hoist line iii because of the slip drive 22 between the two drums. After the bucket is unloaded, it may be held suspended under sheave 23 by the use of brake 2t to prevent reverse or unwinding turning of drum l5, or it may be swung further outwardly from sheave i3 as a pivot by releasing brake 7125i, while holding with brake 25. rEhen to lower the bucket to the eX- treme outer position to begin a new stroke both lines are relieved; or, if it is desired to place the bucket inwardly from that position, the brakes may be used differentially. The friction clutches 22 prevent any back spinning oi" drum EE over drum iii, whether the brake 25 is used or not.

The foregoing description with reference to Figs. l to 4 of the drawings relates to the general arrangement and purpose of the improvement. Figs. 5 to ll serve to amplify the illustration in regard to control of the winding drums, and in regard to provision of automatic means for taking up the slack in cable Ell. referred to as hoist line because it supplements the actual hoist line il but the function of line I4 is mainly to provide an additional suspension means for unloaded bucket whereby the bucket may be swung outwardly from a point 1ocated further out than the normal location of sheave 25 for the hoist line 8. Such performance may take place when the brake is released on winding drum iti for hoist line 8. Then, by relThis cable has been leasing dragline l the bucket swings outwardly` it, as illustrated in Figs. 8 to 1i, include control cylinders 35, 3@ and 3l' having pistons connected with treadle mechanism whereby air or hydraulic pressure may be transmitted through the conduits 3S, 39 and Lili to brake actuating cylinders fl l, il and d3. connected through their pistons to brake band actuating levers Lift. rhe brake bands 45, it and il are indicated in Fig. '7 and used respectively on the brake drums lil and 5E of the winding drums iE, i5 and 2l'.

Drums l5 and 2i are driven through friction clutches 5i and 5?; through the drive gearing 54. Drum l is dri en either by the weight of the bucket through cable ifi, or in the opposite direction to take up slack in cable lli by a counterweight 55, Fig. 5. This counterweight moves up rlhe brake actuating cylinders are and down in guide channels 56 and is connected Drum 58 has a gear connection 59 with drum I6. All control Vcables for the bucket are anchored to their respective drums.

The treadle arrangement shown by Figs. 8 to 11, includes a drag brake pedal 60, and a combination pedal 5I for the hoist line 8 and the extra suspension line I4. The pedal 56 operates the piston of cylinder 35 and the pedal 6I operates either or both of the pistons for the cylinders 36 and 31. If pedal 6I is stepped on centrally, both of brakes 46 and 45 are applied. If the left end of the pedal is stepped on only brake 46 will be applied and if the right end of the pedal is stepped on, only brake 45 will be applied; by sliding the foot to the right or left one or the other of the brakes will be favored. Thus, diierential action between the brakes is easily attained. To allow for lateral tilting of pedal 6 I, it is mounted on the cylinder actuating levers as indicated by Fig. 10. Pedal 6I is pivoted on the levers by ears depending from the pedal and one of these ears has an elongated slot through which one of the levers passes and thus allows for lateral tilting of pedal 6I.

In the operation of the construction shown in Figs. 5 to 11, if there is no requirement for using the extension boom the control of the bucket is exclusive through drums 21 and I5 which respectively operate the dragline 1 and the hoist line 8. The cable I4 which swings from sheave I3 then merely has an idle action being drawn along in one direction by the weight of the bucket when it is lowered, and when the bucket is raised by winding up hoist line 8, the slack in line I4 is taken up by the counterweighted drum I6. Brake band 45 is off under such conditions.

The operation with an increased reach Varies fromy normal merely by making use of cable I4 so as to swing an unloaded bucket outwardly further than normal by making use of brake 45. By stepping on the right end of pedal 6I brake 45 is applied more-or-less while brake 46 is relieved. Then the bucket swings outwardly from the sheave I3, the brake 41 for the dragline at that time being relieved. The bucket is lowered by relieving brake 45 and brake 46 and, by a diiferential use of these brakes, may be placed for 50 the maximum reach, or less. The maximum reach is attained by what is termed casting; that is, permitting the bucket to swing outwardly by its own weight beyond the location of the boom sheaves, and then lowering in timed relation with the swing.

The control means illustrated by Fig. 12 is a simplified arrangement for effecting automatic action in swinging the bucket outwardly from the extension boom. In the arrangement shown by this ligure, a single pedal 62 takes the place of the compound pedal arrangement 6I of Fig. 8. Pedal 62 controls the winding drum I5 for hoist line 8, Fig. 5, in the normal manner, as it does in this type of machine when not equipped with an extension boom.

The normal function of hoist line 8 is to lift loaded or unloaded buckets and also to control their digging angle when drawn toward the machine by the dragline. In Fig. 12 this pedal is shown equipped with a switch-actuating foot rest 53. Thus, when the pedal is depressed in the normal operation of the machine, the element 53 serves to close a brake-actuating switch 64. The brake 65 controlled by this switch serves to place a measured resistance on drum I6 for bucket line I4 leading over the extension boom. Switch 64 is normally held open by a spring, but when the circuit 66 is closed by the switch, a magneticallyoperated valve 61 is opened to admit air to a brake-actuating cylinder 68.

The air supply comes from conduit 69 and passes through a reducing valve 15 before reaching'valve 61. Adjustment of the reducing valve controls the maximum pressure admitted to cylinder 68 and thus the resistance afforded by brake 65 is under control. The counterweight cable 51 is connected through gearing 59 the same as in Fig. "5, with the drum I6 tending always to keep any slack from occurring in cable I4. Cable I4 is overhauled or mildly tensioned by the eifect of the counterweight. It unwinds due to the weight of the empty bucket, but by the application of brake 65, the needed resistance to unwinding of cable I4 is afforded to cause the bucket to swing outwardly from the sheave I3 as a center, according to the extent that line 8 is permitted toreeve out from its winding drum.

The extent of depression of pedal 62 determines the degree of application of the brake to hoist line winding drum I5, as illustrated by Figs. 7 and 8. When loading the bucket brake 65 is ofi and cable I4 is free to run except that it is overhauled by the counterweight to keep free of slack.

Accordingly, the operation of the control means shown by Fig. 12 is incidental to the normal operation of the machine, as though it had no extension boom, but with the extension boom and the equipment shown by Fig. 12 when the hoist line 8 is permitted to reeve out for the purpose 0f lowering the bucket, the winding drum I8 is caused by the friction brake to lag behind the rotation of drum I5 and thus permit the hoist or suspension line I4 to function and cause the bucket to swing outwardly to the end of the eX- tension boom. The brake 65 is set so as to be at all times insuiiicient with the aid of the counterweight to overcome the weight of the unloaded bucket. Accordingly, by paying out on cable 3 as usual, the bucket lowers but the resistance of the brake and the vcounterweight connected with cable I4 is sufficient to cause the bucket to swing from sheave I3, as a center, Fig. 5.

I claim:

l. A dragline excavator comprising a base structure having mounted thereon operating machinery, a mast supported by the base structure, a main boom supported at one end on said structure, an extension boom supported at one end on the outer end of said main boom, suspension stays between the mast and said booms for regulating the diagonal setting of the booms` with reference to the base and the alinement of the booms with each other, dragline equipment comprising a bucket and operating lines therefor including a dragline and a hoist line, the hoist line leading from the bucket to the outer end of the main boom and from thence to the operating machinery, and a .second hoist line leading from the bucket over the end of the extension boom and from there to the operating machinery.

2. A dragline excavator comprising a base structure having mounted thereon operating machinery, a mast supported by the base structure, a main boom supported at one end on said base structure, an `extension boom supported at one end on the outer end of said main boom, suspension stays between the mast and said booms for regulating the diagonal setting of the booms with reference to the base and the alinement of the booms with each other, dragline equipment comprising a bucket and operating lines therefor including a dragline and a hoist line, the hoist line leading from the bucket to the outer end of the main boom and from thence to the operating machinery, and a second hoist line leading from the bucket over the end of the extension boom and from there to the operating machinery, and a pair of winding drums for the hoist lines, a common drive for said winding drums, said drive including a clutch, a friction connection between the two drums whereby one may drive the other with slip, and a brake for each of said drums.

3. A dragline excavating machine equipped with a main boom and an extension boom pivo'ted to the main boom, a dragline bucket with a pair of hoist lines by which said bucket is suspended from the end of the main boom and from the end. of the extension boom, a double winding drum unit for said hoist lines, means for operating said drums differentially, and a dragline for the bucket with operating means therefor.

4. A dragline excavating machine equipped with a main boom and a separate extension boom attached to the main boom, said extension boom being of lighter construction and having less carrying capacity than the main boom, a dragline bucket with a pair of hoist lines by which said bucket issuspended from the end of the main boom and from the end of the extension boom, a double winding drum unit for said hoist lines, means for operating said drums differentially, and a dragline for the bucket with operating means therefor.

5. A dragline excavator having a main boom and an extension boom pivoted to the main boom with suspension means for each of said booms, a dragline bucket, apair of hoist lines for said bucket, one of said lines leading to the main boom and the other oi said lines leading to 'the extension boom, and a winding drum unit having a provision for differentially operating said hoist lines.

-6. A dragline excavating machine provided with a main boom and a separate extension boom mounted on said main boonl, said extension boom being of lighter construction and having less carrying capacity than the main boom, each of said booms having a sheave at its outer end, a drag bucket, a dragiine secured to the bucket, a pair of bucket suspension lines extending from the bucket over said sheaves, operating means for said suspension lines including diierentially operable members for taking up and paying out said lines.

7. A dragline excavating machine provided with a main boom and an extension boom mounted on said main boom7 each of said booms having a sheave at its outer end, a drag bucket, a dragline secured to the bucket, a pair of bucket suspension lines extending from the bucket over said sheaves, operating means for said suspension lines, including differentially operable members for taking up and paying out said lines, a control for said operating means including atreadle mounted for variable differentialy action, and motion transmitting connections between said treadle and the operating means.

8. A dragline excavating machine provided with a main boom and an extension boom mounted on said main boom, a sheave at the outer end of each of said booms, a drag bucket, dragline operating means on said machine with a dragline connection to the bucket, a pair of bucket suspension lines extending from the bucket over said sheaves, operating means for each of `said suspension lines including a counterweight for taking up the slack on one of said suspension lines.

9. A dragline excavating machine provided with a main booin and a-n extension boom mounted on said main boom, said extension boom being of lighter construction and having less carrying capacity than the main boom, a sheave at the outer end of each of said booms, a drag bucket, dragline operating means on said machine with a dragline connection to the bucket, a pair oi bucket suspension lines extending from the bucket over said sheaves, Winding drums for the dragline and each of said suspension lines, power means for driving the dragline drum and for driving one of said suspension line drums, a control for said power means for operating said driven drums together or separately, and means for varying the resistance of the other suspension line Winding drum coincidental with the action of the power-driven suspension line i9. A dragline excavating machine provided with a main boom and an extension boom mounted on said main boom, said extension boom being or lighter construction and having less carrying capacity than the main boom, a drag bucket, suspension means for the drag bucket connected with the main boom, a separate suspension means for the drag bucket connected with the extension boom, control means for actuating said first-mentioned suspension means, and a control for said second suspension means arranged for independent action or for operation in unison With the action of said first-mentioned control.

1l. A dragline excavating machine provided with a main boom and an extension boom mounted on said main boom, a drag bucket, cable Winding means on said machine three cables leading to the bucket, one of said cables extending direct from the machine to the bucket, another of said cables extending from the machine to the bucket over a sheave on the main boom, and another of said cables extending from the machine to the bucket over a sheave on the extension boom, the winding means for said extension boom cable being arranged to partly counterbalance the weight of the bucket, means for adding resistance to said counterbalanced Winding means and comprising a-n air-actuated` brake, means for controlling the operation of the Winding means for the bucket suspension cable passing over the main boom, and said control means being associated with a cooperative control for the bucket suspension cable passing over the extension boom.

l2. A dragline excavating machine comprising a boom supporting structure, a boom mounted thereon, a drag bucket, hoisting means extending from the end of said boom to the bucket, and dragline equipment for effecting the illing motion of the bucket; in combination with an extension boom coupled to the main boom, said extension boom being of lighter construction and having less carrying capacity than the main boom, bucket suspension means extending from the extension boom to the bucket, and manually controllable operating equipment for the hoisting means and the suspension means arranged for transferring part of the load of an empty bucket from the hoisting means to the suspension means.

13. A dragline excavating machine comprising a boom supporting structure, a boom mounted thereon, a drag bucket, hoisting means extending from the end of said boom to the bucket, and dragline equipment for effecting the filling m0- tion of the bucket; in combination with an extension boom coupled to the main boom, said eX- tension boom being of lighter construction and. having less carrying capacity than the main boom, bucket suspension means extending from the extension boom to the bucket, and operating equipment for the hoisting means and the suspension means arranged for transferring part of the load of an empty bucket from the hoisting means to the suspension means.

14. A dragline excavating machine having a boom construction provided with a pair of Widely spaced sheaves lengthwise of the boom, a base for supporting the boom, said boom being of re1ative- 1y lighter construction at the portion between the sheaves than between the inner sheave and the base, a drag bucket, a dragine extending from the base to the bucket, a pair of bucket suspension lines extending from the base over said sheaves to the bucket, and operating means on the base for winding up said suspension lines and arranged to cause the line passing over the inner sheave to carry the major Weight of a loaded bucket and the other suspension line to take less than the full Weight of an unloaded bucket OSCAR J. MARTINSON. 

